sorry Zen Mod, I must have mixed up something.....in one thread you were speaking of SK16 (?) and SK60....

G

as I'm saying HERE and HERE , I have some pairs of 2SJ18+2SK60 in drawer ; using 2SK82 is even better (for quasicomplementary iteration) , due to their higher ratings
of course , one must be aware of rank (bias voltage ) of exact VFets one is having on disposition , so accordingly dimensioning bias net ( exact values in final voltage resistive divider

Quote:

Originally Posted by CeeVee

......
I was just trying to get ZM let us know what he's building his nice shiny new Box with Huge heatsinks for....thought it might be something like this ...with Papa SITs he's got !

nice and shiny (gold sinks) will be something (lips sealed ) , while Babelfish SIT-2 will be made in really old school fashion boxes

these two are on shorter rope , I mean - in line before F6 iteration from post #3431

facts :
1. xformer windings are quadrifilar ; that means somewhat highish capacitance between them
2.lower secondary is sort of sitting on lower rail potential all the time , while
3. upper secondary is floating with output potential ;

result: that (2 vs. 3) , and fact that upper biasing net is really using it's bootstrap function , is really introducing capacitance issue in game

whatever - as Pa said - that's not an issue if you are aware of it - sonic results of F6 are confirming that

our beta testing guys ( you know who you are ) already gave us primary info about that ; with your chip about flipping places of SS , we know more
your truly , Mighty Boy ZM

In a past post, Mr. Pass suggested that two separate transformers can be used instead of a quadrifilar. Will this alleviate some of the issues raised above. I am also speculating that one can readily introduce a deliberate and favourable gain assymetry [tranformers not 100% matched], and their reduced interwinding capacitance [by physical separation] will extend the amp's frequency response beyond 5KHz before employing Pass loop feedback.